Researchers from the University of Hawaii in the United States have pinpointed the year temperatures will hit historic highs in different parts of the world, including Australia.

University of Hawaii researcher Abby Frazier says Sydney would hit its new extreme climate in 2038 and Brisbane four years after that.

"The global average under the business-as-usual, we-don't-do-anything [scenario] is 2047, and if we are able to take aggressive action now to mitigate our CO2, that year gets pushed back to 2069," she said.

Key points:

Research pinpoints the year temperatures could hit historic heights

Climate action could delay timeline by 20 years

Countries in the tropics will feel effects first

Sydney could reach records by 2038

Perth to reach record temperatures by 2042

Melbourne temperatures could reach historic highs by 2045

The University of Hawaii study used nearly 40 different climate-modelling systems to work out when the world's temperatures will surpass those recorded over the past 150 years.

Ms Frazier says it is the first research of its kind and the findings were a surprise.

"We took a very conservative approach to this whole study by using, the absolute min and max values and using all the possible models that are out there," she said.

"We didn't even think that this date [would] happen in the next century so we were really surprised that the 2047 [deadline] was so early. I mean this is within our lifetimes.

"[We were] even more surprised that even if we take action now, the 2069 is still happening within this century."

The study found countries in the tropics like Indonesia and Jamaica could experience changes in climate, or what are termed climate departures,by as early as 2020.

Ryan Longman, who was also part of the research team, says climate change in the tropics will have a ripple effect across the globe.

"Everybody will be affected if the biodiversity in the tropics is affected," he said.